SOUTH COAST AIR QUALITY MANAGEMENT DISTRICT

RULE 463 - ORGANIC LIQUID STORAGE
(Adopted August 15, 1977)(Amended June 1, 1984)(Amended December 7, 1990)
(Amended March 11, 1994)

(a) Applicability

This rule applies to any above-ground stationary tank with a capacity of 75,000 liters (19,815 gallons) or greater used for storage of organic liquids, and any above-ground tank with a capacity between 950 liters (251 gallons) and 75,000 liters (19,815 gallons) used for storage of gasoline.

(b) Definitions

For purposes of this rule, the following definitions apply:

1. CERTIFIED person is a person who has successfully completed the District tank self-inspection program, and who holds a certificate issued by the Executive Officer evidencing that such person is in good standing in this program.
2. EXEMPT COMPOUND is any of the following compounds which have been determined to be non-precursors of ozone:

   (A) Group I

   chlorodifluoromethane (HCFC-22)
   trifluoromethane (HFC-23)
   dichlorotrifluoroethane (HCFC-123)
   2-chloro-1,1,2,2-tetrafluoroethane (HCFC-124)
   pentafluoroethane (HFC-125)
   1,1,2,2-tetrafluoroethane (HFC-134)
   tetrafluoroethane (HFC-134a)
   dichlorofluoroethane (HCFC-141b)
   chlorodifluoroethane (HCFC-142b)
   1,1,1-trifluoroethane (HFC-143a)
   1,1-diflouroethane (HFC-152a)
   cyclic, branched, or linear, completely fluorinated alkanes
   cyclic, branched, or linear, completely fluorinated ethers with no unsaturations
   cyclic, branched, or linear, completely fluorinated tertiary amines with no unsaturations
   sulfur-containing perfluorocarbons with no unsaturations and with sulfur bonds only to carbon and fluorine

   (B) Group II

   carbon tetrachloride
   methylene chloride
   1,1,1-trichloroethane (methyl chloroform)
   trichlorotrifluoroethane (CFC-113)
   dichlorodifluoromethane (CFC-12)
   trichlorofluoromethane (CFC-11)
   dichlorotetrafluoroethane (CFC-114)
   chloropentafluoroethane (CFC-115)

   Use of Group II compounds will be restricted in the future because they are either toxic or potentially toxic, or upper atmospheric ozone depleters, or cause other environmental impacts. Specifically, the District Board has established a policy to phase out chlorofluorocarbons (CFC), methyl chloroform (1,1,1-trichloroethane), and carbon tetrachloride on or before January 1, 1996.

3. GASOLINE means any petroleum distillate having a Reid vapor pressure of 200 mm Hg (3.9 pounds per square inch), or greater.
4. ORGANIC LIQUID is any liquid containing VOCs.
5. PRESSURE RELIEF VALVE (PRV) is a valve which is automatically actuated by upstream static pressure, and used for safety or emergency purposes.
6. SEAL is a closure device between the tank wall and the floating roof edge that controls emissions of volatile organic compounds. Approved floating roof tank seals are categorized as follows:

   (A) Category "A" seals are seals approved by the Executive Officer as most effective in the control of volatile organic compounds and are deemed Best Available Control Technology (BACT) according to the criteria set forth in Attachment A - "Floating Roof Tank Seal Categories."

   (B) Category "B" seals are seals approved by the Executive Officer that are considered more effective than Category "C" seals based on the criteria set forth in Attachment A - "Floating Roof Tank Seal Categories."

   (C) Category "C" seals are seals approved by the Executive Officer which are currently in service but are considered least effective in the control of volatile organic compounds.

7. TANK is any stationary above-ground reservoir or any other stationary above-ground container used for storage of an organic liquid.
8. VAPOR TIGHT is a condition that exists when the reading on a portable hydrocarbon meter is less than 1,000 parts per million (ppm), expressed as methane, above background.
9. VOLATILE ORGANIC COMPOUND (VOC) is any volatile or gaseous chemical compound containing the element carbon, excluding methane, carbon monoxide, carbon dioxide, carbonic acid, metallic carbides, or carbonates, ammonium carbonate, and exempt compounds other than carbon tetrachloride.

(c) Tank Roof Requirements
No person shall place, store or hold in any tank with a capacity of 150,000 liters (39,630 gallons) or greater, any organic liquid having a true vapor pressure of 25.8 mm Hg (0.5 psi) absolute or greater under actual storage conditions, and in any tank of more than 75,000 liters (19,815 gallons) capacity, any organic liquid having a true vapor pressure of 77.5 mm Hg (1.5 psi) absolute or greater under actual storage conditions, unless such tank is a pressure tank maintaining working pressures sufficient at all times to prevent organic vapor loss to the atmosphere, or is designed and equipped with one of the following vapor control devices, which is properly installed and continuously maintained in good operating condition:

1. External Floating Roof

   An external floating roof shall consist of a pontoon-type or double deck-type cover that continuously rests on the surface of the organic liquid and is equipped with a closure device between the tank shell and roof edge. The closure device shall consist of two seals, with one seal placed above the other. The seal below shall be designated as the primary seal, and the seal above shall be designated as the secondary seal. A seal which is not identified on the current list of seals approved by the Executive Officer shall not be installed or used unless the Executive Officer determines that such seal meets the applicable criteria of subparagraphs (c)(1)(A) through (c)(1)(C).

   (A) A closure device on a welded or a riveted tank shell which uses a metallic shoe-type seal as its primary seal shall comply with the following requirements:

   (i) Gaps between the tank shell and the primary seal shall not exceed 1.3 centimeters (1/2 inch) for a cumulative length of 30 percent of the circumference of the tank, and 0.32 centimeter (1/8 inch) for 60 percent of the circumference of the tank. No gap between the tank shell and the primary seal shall exceed 3.8 centimeters (1-1/2 inches). No continuous gap between the tank shell and the primary seal greater than 0.32 centimeter (1/8 inch) shall exceed 10 percent of the circumference of the tank.

   (ii) Gaps between the tank shell and the secondary seal shall not exceed 0.32 centimeter (1/8 inch) for a cumulative length of 95 percent of the circumference of the tank. No gap between the tank shell and the secondary seal shall exceed 1.3 centimeters (1/2 inch).

   (iii) Metallic shoe-type seals installed on or after August 1, 1977 shall be installed so that one end of the shoe extends into the stored organic liquid and the other end extends a minimum vertical distance of 61 centimeters (24 inches) above the stored organic liquid surface.

   (iv) The geometry of the shoe shall be such that the maximum gap between the shoe and the tank shell is no greater than double the gap allowed by the seal gap criteria specified in clause (c)(1)(A)(i) for a length of at least 46 centimeters (18 inches) in the vertical plane above the liquid surface.

   (B) A closure device which uses a resilient toroid-type seal as its primary seal shall comply with the applicable requirements of subparagraph (c)(1)(A).

   (C) The primary and secondary seals shall comply with the following requirements:

   (i) The primary seal envelope shall be made available for unobstructed inspection by the Executive Officer along its circumference. In the case of riveted tanks with resilient toroid-type seals, at least eight such locations shall be made available; for all other types of seals, at least four such locations shall be made available. If the Executive Officer deems it necessary, further unobstructed inspection of the primary seal may be required to determine the seal's condition along its entire circumference.

   (ii) The secondary seal shall be installed in a way that permits the Executive Officer to insert probes up to 3.8 centimeters (1-1/2 inches) in width to measure gaps in the primary seal.

   (iii) The secondary seal shall extend from the roof to the tank shell and shall not be attached to the primary seal.

   (iv) Notwithstanding the secondary and the primary seal requirements of paragraph (c)(1), a secondary or primary seal may be loosened or removed for preventive maintenance, inspection or repair for a period not exceeding 72 hours with prior notification to the Executive Officer .

   (D) All openings in the roof except pressure-vacuum valves, shall provide a projection below the liquid surface to prevent belching, escape, or entrainment of organic liquid, and shall be equipped with a cover, seal or lid. The cover, seal, or lid shall at all times be in a closed position, with no visible gaps, except when the device or appurtenance is in use. Pressure vacuum valves shall be set to within 10 percent of the maximum allowable working pressure of the roof.

   (E) There shall be no holes, tears or openings in the secondary seal or in the primary seal envelope surrounding the annular vapor space enclosed by the roof edge, seal fabric, and secondary seal.

   (F) Any emergency roof drain shall be provided with a slotted membrane fabric cover, or equivalent device, that covers at least nine-tenths (9/10) of the area of the opening.

2. Internal Floating-Type Cover

   A fixed roof tank equipped with an internal floating-type cover shall comply with the following requirements:

   (A) A fixed roof tank with an existing internal floating-type cover approved by the Executive Officer on or before June 1, 1984, shall comply with the requirements applicable at the time such approval was given.

   (B) A fixed roof tank which has an internal floating-type cover installed, modified, or replaced after June 1, 1984, shall have a closure device which consists of either a single liquid mounted primary seal or a primary and a secondary seal. All openings and fittings shall be fully gasketed or controlled in a manner specified by the Executive Officer. The closure device shall control vapor loss with an effectiveness equivalent to a closure device which meets the requirements of subparagraph (c)(1)(A). Seal designs not identified on the current list of seals approved by the Executive Officer shall not be installed or used unless the Executive Officer has given his prior written approval to its installation or use. For purposes of this paragraph, modification includes an identical replacement.

   (C) The concentration of organic vapor in the vapor space above the internal floating-type cover shall not exceed 50 percent of its lower explosive limit (LEL) for those installed prior to June 1, 1984 and 30 percent of its LEL for those installed after June 1, 1984. Compliance shall be verified by the use of an explosimeter.

3. Vapor Recovery System

   A fixed roof tank equipped with a vapor recovery system shall comply with the following requirements:

   (A) Any tank gauging or sampling device on a tank vented to the vapor recovery system shall be equipped with a vapor-tight cover which shall be closed at all times except during gauging or sampling. The roof of such tank shall be properly maintained to be vapor tight with no holes, tears or uncovered openings.

   (B) All piping, valves and fittings shall be constructed and maintained in a vapor-tight condition, in accordance with requirements of other District rules for such equipment.

   (C) For purposes of this paragraph, the efficiency of a vapor recovery system shall be determined by making a comparison of controlled emissions to those emissions which would occur from a fixed cone roof tank holding the same organic liquid without a vapor control or vapor recovery system. The vapor recovery system shall have an efficiency of at least 95 percent by weight.

(d) Other Performance Requirements

1. A person shall not place, store or hold gasoline in any tank, with a capacity of between 950 liters (251 gallons) and 75,000 liters (19,815 gallons) unless such tank is equipped with a pressure-vacuum valve which is set to within 10 percent of the maximum allowable working pressure of the container, or is equipped with a vapor loss control device which complies with the requirements set forth in subdivision (c).
2. The roof of any internal or external floating roof tank shall float on the organic liquid at all times (i.e., free of the roof leg supports) except when the tank is being completely emptied for cleaning, or repair. The process of emptying or refilling, when the roof is resting on leg supports, shall be continuous.
3. If a tank has been gas-freed and is to be refilled with gasoline, the roof shall be refloated with water or by an equivalent procedure approved by the Executive Officer. Paragraphs (d)(2) and (d)(3) shall be inapplicable to gasoline storage tanks at bulk gasoline distribution terminals which do not have:

   (A) existing facilities for treatment of waste water used to refloat the tank roof; or

   (B) facilities for equivalent emission control when refloating the roof with organic liquid.

4. No crude oil containing in excess of 70 ppm by weight of hydrogen sulfide shall be stored in a floating roof tank.
5. A fixed roof tank with an internal floating-type cover or a tank with an external floating roof cover shall not be used for storing organic liquids having a true vapor pressure of 11 psia (569 mm Hg) or greater under actual storage conditions.
6. Replacement of a seal on a floating roof tank shall be allowed only if the replacement seal is chosen from the current list of seals approved by the Executive Officer. Category "A" seals shall be replaced only by Category "A" seals. Category "B" seals shall be replaced only by Category "A" or Category "B" seals. Category "C" seals shall be replaced only by Category "A" or Category "B" seals.

(e) Self-Inspection of Floating Roof Tanks

Any owner or operator of a floating roof tank(s) shall conduct self-inspections of its tank(s) according to the following procedures:

1. Inspection and Maintenance Plan

   (A) On or before September 14, 1994, each owner or operator shall submit an Inspection and Maintenance Plan to the Executive Officer for his/her approval. After September 14, 1994, each owner or operator constructing tank(s) subject to this rule shall submit an Inspection and Maintenance Plan, or a revision of its current Inspection and Maintenance Plan, to the Executive Officer prior to the completion of construction. The Inspection and Maintenance Plan shall include an inventory of tanks subject to this rule, the proposed self-inspection schedule, the number of certified persons to be dedicated to the program, any self-inspection procedures proposed in addition to those required by the District, and a copy of the owner or operator's safety procedures used for floating roof tanks. The tank inventory shall include tank identification number, maximum design capacity, product, shell type, dimensions, seal type and manufacturer, floating roof type, date of construction and location.

2. Identification Requirements

   (A) All tanks subject to this rule shall be clearly and visibly identified by a sign on the outside wall for inventory, inspection and recordkeeping purposes.

   (B) Any change(s) in tank identification shall require prior written approval by the Executive Officer.

3. Owner or Operator Inspection Requirements

   (A) All tanks subject to this rule shall be inspected by a certified person twice per year at 4 to 8 months intervals according to the procedures and guidelines set forth in Attachment B - "Inspection Procedures and Compliance Report Form."

   (B) The primary and secondary seals shall be inspected by a certified person each time a tank is emptied and degassed. Gap measurements shall be performed on an external floating roof tank when the liquid surface is still but not more than 24 hours after the tank roof is refloated.

   (C) The Executive Officer shall be notified in writing at least 2 weeks prior to the start of any tank-emptying or roof-refloating operation for planned maintenance of a tank.

4. Maintenance Requirements

   Any tank which does not comply with any provision of this rule shall be brought into compliance within 72 hours of the determination of non-compliance.

5. Reporting and Recordkeeping Requirements

   (A) All inspections shall be recorded on compliance inspection report forms approved by the Executive Officer as described in Attachment B - "Inspection Procedures and Compliance Report Form."

   (B) All compliance inspection reports and documents shall be submitted to the Executive Officer within 5 working days of completion of the self-inspection.

   (C) If a tank is determined to be in violation of the requirements of this rule, a written report shall be submitted to the Executive Officer within 120 hours of the determination of non-compliance, indicating corrective actions taken to achieve compliance.

   (D) All records of owner or operator inspection and repair shall be maintained at the facility for a period of 3 years and shall be made available to the Executive Officer upon request.

   (E) Emissions Reporting

   (i) An owner or operator shall provide emissions information in a format consistent with Attachment C to the Executive Officer upon request. The requirement shall apply to all organic liquid storage tanks without regard to exemptions specified in subdivision (f).

   (ii) An owner or operator shall provide all upset emissions information associated with product change, repair, and turnover or any other excess emission incidents.

   (iii) An owner or operator shall maintain records of emissions data for all organic liquid storage tanks for the most recent two (2) year period.

(f) Exemptions

The provisions of this rule shall not apply to the following tanks, provided the person seeking the exemption supplies proof of the applicable criteria sufficient to satisfy the Executive Officer:

1. Oil production tanks with a capacity of between 75,000 liters (19,815 gallons) and 159,000 liters (42,008 gallons) which have a properly maintained vapor-tight roof and are equipped with a pressure-vacuum valve which is set within 10 percent of the maximum allowable working pressure of the tank, are exempt from the control requirements of this rule when:

   (A) The organic liquid contents fail to comply with paragraph (b) only when heated for shipment, and such heating occurs for not more than 48 hours and not more than once in any 20-day period; or

   (B) The tank has a monthly average throughput of not more than 30 barrels of oil per day and was constructed prior to June 1, 1984.

2. Tanks being brought into compliance within the time period specified in paragraph (e)(4).

(g) Test Methods

1. Efficiency of a vapor recovery system specified in subparagraph (c)(3)(C) shall be determined according to SCAQMD Test Method 501.1 for the determination of total organic compound emissions. EPA Methods 25 or 25A may be used, as applicable, in place of SCAQMD Test Method 25.1 specified in Method 501.1. An efficiency determined to be less than established by this rule through the use of any of the above-referenced test methods shall constitute a violation of the rule. Baseline emissions shall be calculated by using the criteria outlined in American Petroleum Institute Bulletin 2518.
2. Exempt compounds shall be determined according to SCAQMD Test Method 303. For the purpose of testing the efficiency of a vapor recovery system, exempt compounds shall be determined according to EPA Method 18 or ARB Method 422. Any test method(s) for exempt compounds which cannot be identified through these referenced test methods shall be specified by the owner of operator seeking an exemption and shall be subject to approval in accordance with the procedures set forth in paragraph (g)(6).
3. The Reid vapor pressure specified in paragraph (b)(3) and the Reid vapor pressure used in determining the true vapor pressure limit specified in paragraph (d)(5) shall be determined according to ASTM D-323-82 or California Code of Regulations, Title 13, Section 2297.
4. Vapor tight condition specified in subparagraphs (c)(3)(A) and (c)(3)(B) shall be determined according to EPA's Reference Method 21 subject to the following limitations:

   (A) vapor tight condition shall be determined at a distance of 1 cm. or less from the source ; and

   (B) the soap bubble test shall not be used in lieu of quantitative test methods for vapor tightness determination.

5. The hydrogen sulfide concentration limit specified in paragraph (d)(4) shall be determined according to SCAQMD Method 315.
6. Alternate test methods which are new methods not previously referenced in this rule, or which involve major changes to a referenced test method, may be used if they are approved in advance as a source-specific SIP revision by the United States Environmental Protection Agency and the California Air Resources Board, and have been authorized by the Executive Officer.

SOUTH COAST AIR QUALITY MANAGEMENT DISTRICT

RULE 463 - ADDENDUM

Storage Temperatures Versus Actual Vapor Pressure
(Gravity/Initial Boiling Points Referenced)

ATTACHMENT A

FLOATING ROOF TANK SEAL CATEGORIES

PRIMARY SEALS

Criteria used for categorization of floating roof tank seals:

1. Emission control effectiveness design
2. Ability to maintain contact with tank wall
3. Longevity in service

ATTACHMENT B

INSPECTION PROCEDURES AND COMPLIANCE REPORT FORM

Equipment Needed:

Explosimeter (for internal floating roof tanks), liquid resistant measuring tape or device, tank probe (to measure gaps in tank seals - 1/8 inch, 1/2 inch, 1-1/2 inch), flashlight.

Inspection Procedures

1. The findings of all tank self-inspections, whether completed or not, shall be recorded on the Rule 463 Compliance Report form prescribed by the Executive Officer and submitted to the District's Refinery Section in accordance with the rule's requirements. If an inspection is stopped before completion, indicate the reason for this action in the Comments section of the compliance report form.
2. During compliance inspection, the person(s) conducting the inspection must have a copy of the Permit to Operate or Permit to Construct pertinent to the tank being inspected. Any discrepancies between the permit equipment description and the existing tank or the permit conditions and the actual operating conditions of the tank as verified during inspection must be recorded in the Comments section of the compliance report form.
3. Inspect the ground level periphery of each tank for possible leaks in the tank shell. Complete the tank information section (D) on the report.
4. For external floating roof tanks:

   o From the platform, conduct an overall visual inspection of the roof and check for obvious permit or rule violations. Record the information as shown under section F of the compliance report form.

   o During visual inspection of the roof, check for unsealed roof legs, open hatches, open emergency roof drains or vacuum breakers and record the findings on the report accordingly. Indicate presence of any tears in the fabric of both seals.

   o After the visual inspection, conduct an inspection of the entire secondary seal using the 1/8" and 1/2" probes. Record the gap data in section F(4) of the report.

   o Conduct an inspection of the entire primary seal using the 1/8", 1/2", and 1 1/2" probes. Inspect the primary seal by holding back the secondary seal. Record the gap data in section F(5) of the report.

   o Record all cumulative gaps between 1/8 inch and 1/2 inch ; between 1/2 inch and 1-1/2 inch ; and in excess of 1-1/2 inches, for both primary and secondary seals in section G of the report. Secondary seal gaps greater than 1/2 inch should be measured for length and width, and recorded in Comments under section (J) of the report.

5. For internal floating roof tanks:

   o Using an explosimeter, measure the concentration of the vapor space above the internal floating roof in terms of lower explosive limit (LEL), and record the reading in section (E) of the report.

   o Conduct a visual inspection of the roof openings and the secondary seal, if applicable, and record findings on the report.

6. Complete all necessary calculations and record all required data accordingly on the report.

RULE 463 COMPLIANCE REPORT The 4 page Rule 463 Compliance Report Form does not convert well. A copy of the form may be download as a part of the Rule 463.doc file.

ATTACHMENT C
DATA REPORTING REQUIREMENT FOR ROOF TANKS

The data items shall include, but not be limited to, the following:

* Default values are available from the District

The Data format and order shall be specified and approved by the Executive Officer.

Appendix A
SAMPLE ORGANIC LIQUID STORAGE TANKS
ANNUAL EMISSIONS SAMPLE DATA REPORTING REQUIREMENTS
External Floating Roof Tank

Appendix B

SAMPLE ORGANIC LIQUID STORAGE TANKS
ANNUAL EMISSIONS SAMPLE DATA REPORTING REQUIREMENTS
Internal Floating Roof Tank

Appendix C

SAMPLE ORGANIC LIQUID STORAGE TANKS
ANNUAL EMISSIONS SAMPLE DATA REPORTING REQUIREMENTS
Fixed Roof Tank